Breathalyser breakthrough for asthma patients

He Kitenga, 2005

In a world-first breakthrough for asthma patients, Otago research has shown that new nitric oxide breathalyser technology can be used to improve asthma care.

By using the novel breathing test, which assesses inflammation in the bronchial tubes, asthma treatment with “preventers” can be made much more effective and efficient.

“Our study showed that we can use nitric oxide measurements to take some of the guesswork out of deciding how much treatment to give patients with asthma,” says Professor D. Robin Taylor, head of the Respiratory Research Unit at the Dunedin School of Medicine.

Nitric oxide (NO) is found in exhaled air in very low concentrations in healthy people, but is increased in asthma. With treatment (inhaled steroid), levels go down, and when asthma gets worse, levels rise. By monitoring the levels, treatment can be adjusted appropriately to fit with patients’ requirements much more accurately, says Taylor.

Ninety-four patients completed the study between 2001 and 2004. They were divided into two groups. Half were allocated to have their treatment adjusted using NO measurements. The other half had their treatment adjusted using a conventional approach.

The study was blinded so that patients did not know which group they were in. In the nitric oxide testing group, patients were able to reduce their inhaled steroid drug requirements over 12 months by 40 per cent compared to the control group, but without compromising asthma control.

“In some cases, using nitric oxide results meant that the treatment dose could be reduced substantially, in some cases to almost zero. In other cases, the dose had to be increased – but this was appropriate,” he says. “Up till now, choosing the right dose of inhaled steroid has been based on how asthma patients report their symptoms, but this varies from patient to patient. By measuring inflammation in the bronchial tubes objectively using nitric oxide measurements, the dose of inhaled steroid can be tailored much more accurately.”

Nitric oxide analysers became available in 1998, but this is the first study to show that they can be used to improve patient outcomes. The technology is advancing rapidly. Smaller and cheaper analysers are becoming available, and the test is as easy to perform.

“Our results mean that we can now apply this technology where it matters – in the everyday care of patients. The next step is to see whether it is feasible for GPs to use this technique on a day-to-day basis.”